Improve failed messages navigation from activated group state

[sergioc]

We currently have a very strange way of of indicating a failed messages group is activated and is being browsed. When inside a group, the only indication of which group is being browsed is in the title of the message list container:

This is not sufficient to make it clear a group is being browsed, because:

• the title is not emphasized
• the groups/messages tabs are still visible and used to establish parent/child navigation (definitely not adequate
• we have crumble bar which would be a superior solution, but is left totally unused here

All this gives the impression that the user didn't navigate inside a failed messages group

A better solution is to:

• hide "Error groups" and "Messages" tabs when browsing inside a group
• change title of message list to "X failed messages in group"
• emphasize the title of message list
• place the active group name in crumble bar nav and emphasize it there
• make crumble bar links blue to better indicate they're clickable

[johnsimons]

On top of this, I would also, have the repeated actions that can be performed against a group, they are retry, archive, this links to #280

[sergioc]

@johnsimons 👍